The invention relates to a monolithically integrated circuit of high dielectric strength for electrically coupling isolated circuits.
In most cases circuits operated directly from the mains require electrical decoupling between the input side and the output side with high dielectric strength, e.g. 1.5 kV voltage difference between the two sides. Previously circuits of this kind have been constructed exclusively from discrete components, such as for example transformers, capacitors or opto-couplers. Known semiconductor relays are constructed for example with hybrid-integrated components in which case an opto-coupler consists of a photo-diode, a light conducting path, and a photo-transistor. The use of a capacitor for the aforementioned purpose is disclosed for example in the magazine "Elektor", July/August 1976, 7-48/49 "Kapazitiver Triac-Keppler".
One of the disadvantages of the known circuits is that they are relatively complicated and are also expensive.